(1) Field of the Invention
The invention concerns pump motors, in general, and pump motors with heat dissipation, in particular.
(2) Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
With combustion engines in the field of power-driven vehicles, generally, there are mechanical pumps available, powered from the crankshaft over a toothed belt as a main cooling water pump. As a support or an alternative in a shut-off combustion engine, electric ancillary cooling water pumps are used, which are generally designed as electronically commutated direct-current motors. Main cooling water pumps can also be run electrically. Cooling water pumps are likewise used at hybrid and electric vehicles. There primarily in the cooling circuit of an accumulator cooling system. Electronically commutated direct current motors, generally, feature printed circuit boards with electronic assembly parts, especially performance components for the commutation of the stator winding. In these components, depending on the engine-power class, more or less heat develops, which should be dissipated as easily as possible, in order to avoid damages through overheating. It is common to lead the heat capacity over the separation can into the transporting medium, provided that the medium can serve as a heat sink. Due to the continuous recirculation of the medium, the heat is transported from the pump chamber through an enforced convection and, for instance, to a vehicle cooling system. Since for the heat transmission only a relatively small surface is available, just a limited heat dissipation capacity can be reached, whereby the capabilities of the pump are restricted.